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EP: Fachverband Extraterrestrische Physik
EP 2: Astrophysics / Exoplanets and Astrobiology
EP 2.6: Talk
Monday, March 21, 2022, 17:45–18:00, EP-H1
Planetary interiors via Love-number determined from radial velocities — •Lia Marta Bernabò and Szilárd Csizmadia — DLR Berlin, Institut für Planetenforschung (Deutsches Zentrum für Luft-und Raumfahrt) - Rutherfordstr. 2, 12489 Berlin
We study the inner structure of planets by determining the Love numbers kn and hn (Love, 1911), which describes the susceptibility of their shape to change in response to a tidal and rotational potential. The second degree Love number k2 is highly sensitive to the thickness of the interior layers and rheology of the planet and it is proportional to the concentration of mass towards the centre of the planet, therefore it is used to infer the internal structure of the body. We will present the method how to analyze the radial velocity curve in presence of apsidal motion caused by tidal interaction between the star and the planet, and by general relativity. The former one can be linked to the Love-number k2 (Kopal, 1959) which constrains the planetary interior as a third measurable parameter beyond the mass and radius (Baumeister et al., 2020). We also study the effect of the rotationally and tidally distorted stellar shape on the radial velocity curves. This causes a distortion on the RV-shape as well, and leads to the presence of an apparent eccentric orbit in the RV-curve. We show that the correct estimate of this effect must be taken into account and some other studies overestimated its amplitude and significance. Finally, we show our first results when we applied our method to real systems.